The traditional analysis of the basic version of the double-slit experiment leads to the conclusion that wave-particle duality is a fundamental fact of nature. However, such a conclusion means to imply that we are not only required to have two contradictory pictures of reality but also compelled to abandon the objectiveness of the truth values, “true” and “false”. Yet, even if we could accept wave-like behavior of quantum particles as the best explanation for the (...) build-up of an interference pattern in the double-slit experiment, without the objectivity of the truth values we would never have certainty regarding any statement about the world. The present paper discusses ways to reconcile the correct description of the double-slit experiment with the objectiveness of “true” and “false”. (shrink)

A number of papers on wave-particle duality has appeared since the two-prism experiment was performed by Mizobuchi and Ohtake, based on a suggestion by Ghose, Home, and Agarwal. Against this backdrop, the present paper provides further clarification of the key issues involved in the analysis of the two-prism experiment. In the process, we present an overview of wave-particle duality vis-a vis Bohr's complementarity principle.

Some modified two-slit interference experiments were carried out showing an apparent paradox in wave–particle duality. In a typical such experiment, the screen, where the interference pattern is supposed to be formed, is replaced by a converging lens. The converging lens forms the images of the two slits at two spatially separated detectors. It was claimed that each of these two detectors give information about which slit a photon came from, even though they come from (...) the region of interference. These experiments generated a lot of debate. The various refutations pointed out that the controversial claims involved some questionable assumptions. However the refutations were largely philosophical in nature, and one may like to substantiate those with arguments which are testable, at least in principle. Here such an experiment is theoretically analyzed by introducing path markers which are two orthogonal polarization states of the photon. Analyzing the polarization at the two detectors shows that the photons which give rise to interference, and reach a particular detector, always come from both the slits. This provides clarity in understanding such experiments by making use of testable quantum correlations. (shrink)

This chapter contains sections titled: * Introduction * The Two-Slit Experiment and Wave-Particle Duality * Heisenberg’s Uncertainty Principle * Schrödinger’s Cat * The Einstein-Podolsky-Rosen Experiment * Interpretation: Quantum Reality? * Critical Realism in Science and Theology * Determinism, Human Free Will, and Divine Action * Consonance with Christian Doctrine * References * Further Reading.

A modified version of Young’s experiment by Shahriar Afshar indirectly reveals the presence of a fully articulated interference pattern prior to the post-selection of a particle in a “which-slit” basis. While this experiment does not constitute a violation of Bohr’s Complementarity Principle as claimed by Afshar, both he and many of his critics incorrectly assume that a commonly used relationship between visibility parameter V and “which-way” parameter K has crucial relevance to his experiment. It is (...) argued here that this relationship does not apply to this experimental situation and that it is wrong to make any use of it in support of claims for or against the bearing of this experiment on Complementarity. (shrink)

We consider the compatibility of the Wootters and Zurek development of information theory as applied to the two-slit experiment with the principle of complementarity. We also consider the limitations of aspects of Wootters and Zurek's analysis, and, independently of complementarity, the extent to which Wootters and Zurek's information theory can be considered a fundamental interpretation of the quantum theory (as applied to particle-wave duality). The question of particle-wave uncertainty relations will also be taken (...) up. (shrink)

In a quantum mechanical two-slit experiment one can observe a single photon simultaneously as particle (measuring the path) and as wave (measuring the interference pattern) if the path and the interference pattern are measured in the sense of unsharp observables. These theoretical predictions are confirmed experimentally by a photon split-beam experiment using a modified Mach—Zehnder interferometer.

Bell's theorem is believed to establish that the quantum mechanical predictions do not generally admit a causal representation compatible with Einsten's principle of separability, thereby proving incompatibility between quantum mechanics and relativity. This interpretation is contested via two convergent approaches which lead to a sharp distinction between quantum nonseparability and violation of Einstein's theory of relativity.In a first approach we explicate from the quantum mechanical formalism a concept of “reflected dependence.” Founded on this concept, we produce a causal representation of (...) the quantum mechanical probability measure involved in Bell's proof, which is clearly separable in Einstein's sense, i.e., it does not involve supraluminal velocities, and nevertheless is “nonlocal” in Bell's sense. So Bell locality and Einstein separability aredistinct qualifications, and Bell nonlocality (or Bell nonseparability) and Einstein separability arenot incompatible. It is then proved explicitly that with respect to the mentioned representation Bell's derivation does not hold. So Bell's derivation does notestablish thatany Einstein-separable representation is incompatible with quantum mechanics. This first—negative—conclusion is asyntactic fact.The characteristics of the representation and of the reasoning involved in the mentioned counterexample to the usual interpretation of Bell's theorem suggest that the representation used—notwithstanding its ability to bring forth the specified syntactic fact—isnot factually true. Factual truth and syntactic properties also have to be radically distinguished in their turn. So, in a second approach, starting from de Broglie's initial relativistic model of a microsystem, a deeper, factually acceptable representation is constructed. The analyses leading to this second representation show that quantum mechanics does indeed involve basically a certain sort of nonseparability, called here de Broglie-Bohr quantum nonseparability. But the de Broglie-Bohr quantum nonseparability is shown to stem directly from the relativistic character of the considerations which led Louis de Broglie to the fundamental relation p = h/λ,thereby being essentially consistent with relativity. As to Einstein separability, it appears to be a still insufficiently specified conceptof which a future, improved specification, will probably be explicitly harmonizable with the de Broglie-Bohr quantum nonseparability.The ensemble of the conclusions obtained here brings forth a new concept of causality, a concept offolded, zigzag, reflexive causality, with respect to which the type of causality conceived of up to now appears as aparticular case of outstretched, one-way causality. The reflexive causality is found compatible with the results of Aspect's experiment, and it suggests new experiments.Considered globally, the conclusions obtained in the present work might convert the conceptual situation created by Bell's proof into a process of unification of quantum mechanics and relativity. (shrink)

Shahriar S. Afshar claimed that his 2007 modified version of the double-slit experiment violates complementarity. He makes two modifications to the standard double-slit experiment. First, he adds a wire grid that is placed in between the slits and the screen at locations of interference minima. The second modification is to place a converging lens just after the wire grid. The idea is that the wire grid implies the existence of interference minima, while the lens can simultaneously (...) obtain which-way information. More recently, Cramer argued that the experiment bolstered the Transactional Interpretation of Quantum mechanics. His argument scrutinizes Bohr’s complementarity in favor of TIQM. We analyze this experiment by simulation using the path integral formulation of quantum mechanics and find that it agrees with the wave-particle duality relation given by Englert, Greenberg and Yasin. We conclude that the use of Afshar’s experiment to provide a testbed for quantum mechanical interpretations is limited. (shrink)

A prominent way through which wave-particle duality has been ascribed to photons is by illustrating their “wave-like” behaviour in the Mach-Zehnder interferometer and “particle-like” behaviour in the anti-correlation experiment. This duality has been formulated in two ways. Some have based the claim on the complementarity principle. This formulation, however, has already been shown to be problematic. Others have made a much simpler duality claim by considering that single-photons are analogous to waves and (...) particles in the above experiments. I criticise this formulation by arguing that the analogies cannot be distinctly established. Thus, this duality claim is found to be unsubstantiated. (shrink)

We report on the simultaneous determination of complementary wave and particle aspects of light in a double-slit type “welcher-weg” experiment beyond the limitations set by Bohr’s Principle of Complementarity. Applying classical logic, we verify the presence of sharp interference in the single photon regime, while reliably maintaining the information about the particular pinhole through which each individual photon had passed. This experiment poses interesting questions on the validity of Complementarity in cases where measurements techniques that (...) avoid Heisenberg’s uncertainty principle and quantum entanglement are employed. We further argue that the application of classical concepts of waves and particles as embodied in Complementarity leads to a logical inconsistency in the interpretation of this experiment. (shrink)

Simultaneous observation of the wave-like and particle-like aspects of the photon in the double-slit experiment is unallowed. The underlying reason behind this limitation is not understood. In this paper, we explain this unique behavior by considering the communicational properties of the photons. Photons have three independently adjustable properties (energy, direction, and spin) that can be used to communicate messages. The double-slit experiment setup fixes two of these properties and confines the single photon’s capacity for (...) conveying messages to no more than one message. With such a low communication capacity, information theory dictates that measurements associated only with one proposition can obtain consistent results, and a second measurement associated with an independent proposition must necessarily lead to randomness. In the double-slit example, these are the wave or particle properties of the photon. The interpretation we offer is based on the formalism of information theory and does not make use of Heisenberg’s uncertainty relation in any form. (shrink)

By probability theory the probability space to underlie the set of statistical data described by the squared modulus of a coherent superposition of microscopically distinct (sub)states (CSMDS) is non-Kolmogorovian and, thus, such data are mutually incompatible. For us this fact means that the squared modulus of a CSMDS cannot be unambiguously interpreted as the probability density and quantum mechanics itself, with its current approach to CSMDSs, does not allow a correct statistical interpretation. By the example of a 1D completed scattering (...) and double slit diffraction we develop a new quantum-mechanical approach to CSMDSs, which requires the decomposition of the non-Kolmogorovian probability space associated with the squared modulus of a CSMDS into the sum of Kolmogorovian ones. We adapt to CSMDSs the presented by Khrennikov (Found. Phys. 35(10):1655, 2005) concept of real contexts (complexes of physical conditions) to determine uniquely the properties of quantum ensembles. Namely we treat the context to create a time-dependent CSMDS as a complex one consisting of elementary (sub)contexts to create alternative subprocesses. For example, in the two-slit experiment each slit generates its own elementary context and corresponding subprocess. We show that quantum mechanics, with a new approach to CSMDSs, allows a correct statistical interpretation and becomes compatible with classical physics. (shrink)

Light is puzzling in modern physics–witness wave-particle duality, the two-slit experiment, and the invariant speed of light. These puzzles are not intrinsic to light but arise from overly narrow views of light. Disregarding the expansive, unitary nature of light that informs everyday experience, modern physics treats light as if it were self-bounded and separable. Further, physics assumes that light is not complicit with observations of light, that the two are separable. By likening light to light-illuminated (...) entities, these attitudes set the stage for puzzles. When,however, conceptions of light are aligned with visual experience, those puzzles become occasions of understanding.This is because visual experience already embodies that aspect of light which physics finds so anomalous: nonseparability. Light's interactive vastness shows up wherever light shows up, and because no observer can back away from light or step outside its integrative embrace, different parts of light cannot be lifted out ofthe observation as distinct – i.e., distinctly-observed – entities. (shrink)

Quantum trajectory-based descriptions of interference between two coherent stationary waves in a double-slit experiment are presented, as given by the de Broglie–Bohm and modified de Broglie–Bohm formulations of quantum mechanics. In the dBB trajectory representation, interference between two spreading wave packets can be shown also as resulting from motion of particles. But a trajectory explanation for interference between stationary states is so far not available in this scheme. We show that both the dBB and MdBB trajectories are (...) capable of producing the interference pattern for stationary as well as wave packet states. However, the dBB representation is found to provide the ‘which-way’ information that helps to identify the hole through which the particle emanates. On the other hand, the MdBB representation does not provide any which-way information while giving a satisfactory explanation of interference phenomenon in tune with the de Broglie’s wave particle duality. By counting the trajectories reaching the screen, we have numerically evaluated the intensity distribution of the fringes and found very good agreement with the standard results. (shrink)

Recently, Bohr’s complementarity principle was assessed in setups involving delayed choices. These works argued in favor of a reformulation of the aforementioned principle so as to account for situations in which a quantum system would simultaneously behave as wave and particle. Here we defend a framework that, supported by well-known experimental results and consistent with the decoherence paradigm, allows us to interpret complementarity in terms of correlations between the system and an informer. Our proposal offers formal definition and (...) operational interpretation for the dual behavior in terms of both nonlocal resources and the couple work-information. Most importantly, our results provide a generalized information-based trade-off for the wave–particle duality and a causal interpretation for delayed-choice experiments. (shrink)

Interference of more and more massive objects provides a spectacular confirmation of quantum theory. It is usually regarded as support for “wave–particle duality” and in an extension of this duality even as support for “complementarity”. We first give an outline of the historical development of these notions. Already here it becomes evident that they are hard to define rigorously, i.e. have mainly a heuristic function. Then we discuss recent interference experiments of large and complex molecules which (...) seem to support this heuristic function of “duality”. However, we show that in these experiments the diffraction of a delocalized center-of-mass wave function depends on the interaction of the localized structure of the molecule with the diffraction element. Thus, the molecules display “dual features” at the same time, which contradicts the usual understanding of wave–particle duality. We conclude that the notion of “wave–particle duality” deserves no place in modern quantum physics. (shrink)

Is it possible that the most famous critic of quantum mechanics actually invented most of its fundamentally important concepts? -/- In his 1905 Brownian motion paper, Einstein quantized matter, proving the existence of atoms. His light quantum hypothesis showed that energy itself comes in particles (photons). He showed energy and matter are interchangeable, E = mc2. In 1905 Einstein was first to see nonlocality and instantaneous action-at-a-distance. In 1907 he saw quantum “jumps” between energy levels in matter, six years before (...) Bohr postulated them in his atomic model. Einstein saw wave-particle duality and the “collapse” of the wave in 1909. And in 1916 his transition probabilities for emission and absorption processes introduced ontological chance when matter and radiation interact, making quantum mechanics statistical. He discovered the indistinguishability and odd quantum statistics of elementary particles in 1925 and in 1935 speculated about the nonseparability of interacting identical particles. -/- It took physicists over twenty years to accept Einstein’s light-quantum. He explained the relation of particles to waves fifteen years before Heisenberg matrices and Schrödinger wave functions. He saw indeterminism ten years before the uncertainty principle. And he saw nonlocality as early as 1905, presenting it formally in 1927, but was ignored. In the 1935 Einstein-Podolsky-Rosen paper, he explored nonseparability, which was dubbed “entanglement” by Schrödinger. The EPR paper has gone from being irrelevant to Einstein’s most cited work and the basis for today’s “second revolution in quantum mechanics.” -/- In a radical revision of the history of quantum physics, Bob Doyle develops Einstein’s idea of objective reality to resolve several of today’s most puzzling quantum mysteries, including the two-slit experiment, quantum entanglement, and microscopic irreversibility. (shrink)

We review the present status of wave-particle duality of single-photon states in the context of some recent experiments. In particular, Bohr's complementarity principle is critically reexamined. It is explained in detail how this principle is confronted in these experiments and how a contradiction with the notion of “mutual exclusiveness” of classical wave and particle pictures emerges.

A modified version of Young's experiment by Shahriar Afshar demonstrates that, prior to a ``which-way'' measurement indicating which slit a particle goes through, an interference pattern exists. It has been claimed that this result constitutes a violation of the Principle of Complementarity. This paper discusses the implications of this experiment and considers how Cramer's Transactional Interpretation accomodates the result. It is shown that the Afshar experiment is isomorphic in key respects to a a spin one-half (...) particle prepared as ``spin up along x'' and post-selected in a specific state of spin along z. It is concluded that Bohr would have had no more problem accounting for the Afshar result than he would in accounting for the aforementioned pre- and post-selection spin experiment, in which the particle's preparation state is confirmed by a nondestructive measurement prior to post-selection. (shrink)

The electron double-slit interference is re-examined from the point of view of temporal topos. Temporal topos (or t-topos) is an abstract algebraic (categorical) method using the theory of sheaves. A brief introduction to t-topos is given. When the structural foundation for describing particles is based on t-topos, the particle-wave duality of electron is a natural consequence. A presheaf associated with the electron represents both particle-like and wave-like properties depending upon whether an object in the (...) site (t-site) is specified (particle-like) or not (wave-like). It is shown that the localization of the electron at one of the slits is equivalent to choosing a particular object in the t-site and that the electron behaves as a wave when it passes through a double-slit because there are more than one object in the t-site. Also, the single-slit diffraction is interpreted as a result of the possibility of many different ways of factoring a morphism between two objects. (shrink)

The assertion that an experiment by Afshar et al. demonstrates violation of Bohr’s Principle of Complementarity is based on the faulty assumption that which-way information in a double-slit interference experiment can be retroactively determined from a future measurement.

Bohmian mechanics, a hydrodynamic formulation of the quantum theory, constitutes a useful tool to understand the role of the phase as the mechanism responsible for the dynamical evolution displayed by quantum systems. This role is analyzed and discussed here in the context of quantum interference, considering to this end two well-known scenarios, namely Young’s two-slit experiment and Wheeler’s delayed choice experiment. A numerical implementation of the first scenario is used to show how interference in a coherent superposition (...) of two counter-propagating wave packets can be seen and explained in terms of an effective model consisting of a single wave packet scattered off an attractive hard wall. The outcomes from this model are then applied to the analysis of Wheeler’s delayed choice experiment, also recreated by means of a reliable realistic simulation. Both examples illustrate quite well how the Bohmian formulation helps to explain in a natural way aspects of the quantum theory typically regarded as paradoxical. In other words, they show that a proper understanding of quantum phase dynamics immediately removes any trace of unnecessary artificial wave-particle arguments. (shrink)

This volume brings together eleven essays by the distinguished philosopher of science, Peter Achinstein. The unifying theme is the nature of the philosophical problems surrounding the postulation of unobservable entities such as light waves, molecules, and electrons. How, if at all, is it possible to confirm scientific hypotheses about "unobservables"? Achinstein examines this question as it arose in actual scientific practice in three nineteenth-century episodes: the debate between particle and wave theorists of light, Maxwell's kinetic theory of gases, (...) and J.J. Thomson's discovery of the electron. The book contains three parts, each devoted to one of these topics, beginning with an essay presenting the historical background of the episode and an introduction to the philosophical issues. There is an illuminating evaluation of various scientific methodologies, including hypothetico-deductivism, inductivism, and the method of independent warrant which combines features of the first two. Achinstein assesses the philosophical validity of both nineteenth-century and modern answers to questions about unobservables, and presents and defends his own solutions. (shrink)

It is shown that the lattice-theoretic distributive law does not fail to hold in the two slit-experiment for the general case offinite slit widths and for a position measurement which localizes the observed particle to afinite region of the screen. Comments are made on previous and less general discussions of the case considered.

We respond to criticism of our paper “Paradox in Wave-Particle Duality for Non-Perturbative Measurements”. We disagree with Steuernagel’s derivation of the visibility of the Afshar experiment. To calculate the fringe visibility, Steuernagel utilizes two different experimental situations, i.e. the wire grid in the pattern minima and in the pattern maxima. In our assessment, this procedure cannot lead to the correct result for the complementarity properties of a wave-particle in one particular experimental set-up.

Both theory and experiments indicate that the vacuum is not a state of empty space, but is populated by electromagnetic fluctuations at a lowest nonzero level, the Zero Point Energy (ZPE). This debouches into considerable changes of fundamental physics, as shown by a revised quantum electrodynamic theory (RQED) applied to elementary particles, and by a revised ZPE frequency spectrum applied to the expanding universe. The Standard Model based on a vacuum state of empty space is thus replaced by RQED, thereby (...) resulting in massive elementary particles from the beginning, independently of the theory by Higgs. Also the basic properties of the Higgs-like particle detected at CERN can be reproduced by RQED. It further leads to new fundamental results beyond the theories by Dirac and Higgs, such as to a deduced value of the elementary net charge, magnetic confinement of charged particle configurations, intrinsic local particle charges, photon spin with a very small but nonzero photon rest mass, and needle-like particle-wave properties which contribute to the understanding of the photoelectric effect and two-slit experiments. The real macroscopic pressure due to the revised ZPE frequency distribution further influences the dynamics of the expanding universe, by the ZPE photon pressure gradient acting as dark energy, and the ZPE photon energy density acting as dark matter. This results in a model being consistent with the observed scale, the rate of expansion, and the stability of a flat expanding observable universe. EWW141009DXN. (shrink)

A local interpretation of quantum mechanics is presented. Its main ingredients are: first, a label attached to one of the “virtual” paths in the path integral formalism, determining the output for measurement of position or momentum; second, a mathematical model for spin states, equivalent to the path integral formalism for point particles in space time, with the corresponding label. The mathematical machinery of orthodox quantum mechanics is maintained, in particular amplitudes of probability and Born’s rule; therefore, Bell’s type inequalities theorems (...) do not apply. It is shown that statistical correlations for pairs of particles with entangled spins have a description completely equivalent to the two slit experiment, that is, interference instead of non locality gives account of the process. The interpretation is grounded in the experimental evidence of a point like character of electrons, and in the hypothetical existence of a wave like, the de Broglie, companion system. A correspondence between the extended Hilbert spaces of hidden physical states and the orthodox quantum mechanical Hilbert space shows the mathematical equivalence of both theories. Paradoxical behaviour with respect to the action reaction principle is analysed, and an experimental set up, modified two slit experiment, proposed to look for the companion system. (shrink)

The Parallax View is Slavoj Zizek's most substantial theoretical work to appear in many years; Zizek himself describes it as his magnum opus. Parallax can be defined as the apparent displacement of an object, caused by a change in observational position. Zizek is interested in the "parallax gap" separating two points between which no synthesis or mediation is possible, linked by an "impossible short circuit" of levels that can never meet. From this consideration of parallax, Zizek begins a rehabilitation of (...) dialectical materialism.Modes of parallax can be seen in different domains of today's theory, from the wave-particle duality in quantum physics to the parallax of the unconscious in Freudian psychoanalysis between interpretations of the formation of the unconscious and theories of drives. In The Parallax View, Zizek, with his usual astonishing erudition, focuses on three main modes of parallax: the ontological difference, the ultimate parallax that conditions our very access to reality; the scientific parallax, the irreducible gap between the phenomenal experience of reality and its scientific explanation, which reaches its apogee in today's brain sciences ; and the political parallax, the social antagonism that allows for no common ground. Between his discussions of these three modes, Zizek offers interludes that deal with more specific topics--including an ethical act in a novel by Henry James and anti-anti-Semitism.The Parallax View not only expands Zizek's Lacanian-Hegelian approach to new domains but also provides the systematic exposition of the conceptual framework that underlies his entire work. Philosophical and theological analysis, detailed readings of literature, cinema, and music coexist with lively anecdotes and obscene jokes. (shrink)

Why is there a 'hard problem' of consciousness? Why do we seem unable to grasp intuitively that physical brain processes can be identical to experiences? Here I comment on the 'meta-problem' (Chalmers, 2018), based on previous ideas (Storm, 2014; 2018). In short: humans may be 'inborn dualists' ('neuroscepticism'), because evolution gave us two (types of) brain systems (or functional modes): one (Sp) for understanding relatively simple physical phenomena, and another (Sm) specialized for mental phenomena. Because Sp cannot deal with the (...) immense complexity of the brain processes underlying consciousness, it represents them as fundamentally different from nonmental physical phenomena (dualist intuition), using 'simulations' to produce 'Sm-type understanding'/predictions that seems radically different from 'Sp-type understanding'. (By analogy, different sensory modalities, handled by distinct brain systems, evoke qualitatively different experiences.) Brain systems for Sp representations of our brain processes never evolved, because they would be useless. When lacking a single 'template' matching different aspects of reality (objective vs. subjective = simulated), complementary 'models' are needed ('neuro-complementarity'), like the wave–particle duality in quantum mechanics. Thus, it seems plausible that Sp and Sm evolved because they were needed to cope with different challenges, and that 'problem intuitions' are side effects of these useful but different brain systems. (shrink)

The book deals with expounding the nature of Reality as it is understood in contemporary times in Quantum Physics. It also explains the classical Indian theory of Śūnya in its diverse facets. Thereafter it undertakes comparison between the two which is an area of great topical interest. It is a cross-disciplinary study by erudite Indian and western scholars between traditional Indian knowledge system and contemporary researches in Physical sciences. It points out how the theory of ‘Śūnyatā has many seminal ideas (...) and theories in common with contemporary Quantum Physics. The learned authors have tried to dissolve the “mysteries” of Quantum Physics and resolved its “weird paradoxes” with the help of theory of Śūnyatā. The issue of non-separability or entanglement has been approached with the help of the Buddhist theory of Pratītyasamutpāda. The paradoxical situation of “wave-particle duality” has been explained with the help of Upaniṣadic theory of complementarity of the two opposites. The measurement problem represented by “Schrodinger’s cat” has been dealt with by resorting to two forms of the calculation of probabilities. Some writers have argued for Śūnyatā-like non-essentialist position to understand quantum reality. To make sense of quantum theory some papers provide a happy symbiosis of technical understanding and personal meditative experience by drawing multifarious parallels. This book will be of interest to philosophically inclined physicists and philosophers with interest in quantum mechanics. (shrink)

Nagel has argued that the ‘mind-body’ problem, as traditionally conceived, is insoluble. His challenge to philosophers is to devise a metaphysical scheme that incorporates materialist concepts in describing first person experience and mentalistic concepts in describing third person experience, such that the internal relations between the concepts thereby constructed are necessary. Nagel's own suggestion, a scheme not unlike the ‘underlying process’ schemes of the physical sciences, seems to lead him towards a covert materialism. Progress can be made in meeting the (...) challenge by tackling the problem first by taking the units in each ‘sphere’ to be brains and persons. I show that a metaphysics based on the metaphor of person defined tasks and materially defined tools does satisfy both Nagel's challenge conditions. To devise a scheme for qualia and brain-states I turn back to Locke's presentation of the primary/secondary quality distinction. This depends on the concept of a causal power, grounded in material states of the world. While this scheme is inadequate, a variation, based on Gibson's concept of an affordance, and drawing on Bohr's resolution of the seeming incompatibility between wave and particle ontologies for physics, is promising. The world, whatever it is, affords material states to our perceptual apparatus, and mental states to our proprioceptual apparatus. The mental states/brain states duality is not a duality of types of states, which might stand in causal relations to one another, but is a duality of means of access to two classes of affordances of whatever the world is. There is no mind-body problem in the traditional sense, namely ‘How could a material state cause or be caused by a mental state?’. (shrink)

A new probability interpretation of interference phenomena in the double-slit experiment is proposed. It differs from the standard interpretation (based on elementary events happening in complementary, mutually exclusive setups—arrivals of waves to the screen when one of the slits is closed) which encounters the “paradox” that the law of total probability is violated. This new interpretation is free of such difficulties and paradoxes since it is based on compatible elementary events (events happening in the same setup in which (...) happenall events considered—arrivals of quantons to the screen when both slits are open). Quantum objects—quantons—possess simultaneously particle and wave properties. Compatible statistical interpretation synthesizes in a consistent way the superposition principle for waves and the law of total probability applied to compatible events. Such synthesis is a theoretical expression of de Broglie's observation, now fully confirmed by experiments, that the interference fringes obtained on a photographic plate result from an infinite number of tiny local spots which display arrival of quantons, while the set of fringes is a statistical effect of the wave aspect. (shrink)

David Bohm published his “Suggested Interpretation of Quantum Theory in Terms of Hidden Variables” some twenty five years after Louis de Broglie first presented his similar Pilot Wave theory of quantum mechanics. In the following 30 years what became known as the de Broglie–Bohm approach to quantum theory was to a large extent ignored within the physics community. Even David Bohm himself became somewhat disillusioned with the lack of impact of his interpretation of quantum theory and he directed his (...) interest elsewhere. But some 27 years after Bohm had published his interpretation of quantum theory, interest was rekindled in part by new, detailed calculations that demonstrated clearly and graphically, exactly how his interpretation explained quantum phenomena in terms of well defined individual particle trajectories. These computations encompassed two-slit interference, quantum tunnelling, neutron interferometry, Wheeler’s delayed choice experiment, orbital and intrinsic angular momentum, quantum measurement and Einstein–Podolsky–Rosen nonlocal correlations for orbital angular momentum, intrinsic angular momentum and correlated particle interferometry. Since then, the acceptance of the validity of de Broglie–Bohm theory has steadily grown, as has the interest in the consequences of the approach. For my contribution to the current celebratory volume I was asked to provide a personal review specifically of this novel work within its historical context of the last quarter of the twentieth century. (shrink)

I argue that quantum optical experiments that purport to refute Bohr’s principle of complementarity fail in their aim. Some of these experiments try to refute complementarity by refuting the so called particle–wave duality relations, which evolved from the Wootters–Zurek reformulation of BPC. I therefore consider it important for my forgoing arguments to first recall the essential tenets of BPC, and to clearly separate BPC from WZPC, which I will argue is a direct contradiction of BPC. This leads (...) to a need to consider the meaning of particle–wave duality relations and to question their fundamental status. I further argue that particle and wave complementary concepts are on a different footing than other pairs of complementary concepts. (shrink)

The question of the relation between the amplitude of the photon vector potential and its angular frequency is analyzed. The analogy between the relativistic quantum mechanical equations for a massles particle and those governing the photon vector potential appears clearly. Finally, the virtual electromagnetic waves associated with the photon and predicted by de Broglie, Bohr, and other appear naturally as a result of the photon vector potential quantification.

We describe a new class of experiments designed to probe the foundations of quantum mechanics. Using quantum controlling devices, we show how to attain a freedom in temporal ordering of the control and detection of various phenomena. We consider wave–particle duality in the context of quantum-controlled and the entanglement-assisted delayed-choice experiments. Then we discuss a quantum-controlled CHSH experiment and measurement of photon’s transversal position and momentum in a single set-up.

(1980). The development of attitudes to the wave-particle duality of light and quantum theory, 1900–1920. Annals of Science: Vol. 37, No. 1, pp. 59-79.

An elementary review of the origin of quantum theory, with focus on the nature of the quantum dynamic variables, reveals the essential wave-likeness of quantum dynamics. The introduction of the concept of point-particle entities resulted from over-use of classical perspectives, and an issue of language: conflation of the concepts of point-particle localization, and discreteness of quantum detections. Keeping in mind the distinction between point-localization and discreteness of quantum exchange, it is clear that there is no experimental evidence (...) for point-localization. A simple review of the origin of quantum theory, and review of several experiments designed to explore "wave-particle duality" and "complementarity" support this perspective. Normal 0 false false false EN-AU X-NONE X-NONE MicrosoftInternetExplorer4. (shrink)

In spite of the interference manifested in the double-slit experiment, quantum theory predicts that a measure of interference defined by Sorkin and involving various outcome probabilities from an experiment with three slits, is identically zero. We adapt Sorkin’s measure into a general operational probabilistic framework for physical theories, and then study its relationship to the structure of quantum theory. In particular, we characterize the class of probabilistic theories for which the interference measure is zero as ones in (...) which it is possible to fully determine the state of a system via specific sets of ‘two-slit’ experiments. (shrink)

An interesting link between two very different physical aspects of quantum mechanics is revealed; these are the absence of third-order interference and Tsirelson’s bound for the nonlocal correlations. Considering multiple-slit experiments—not only the traditional configuration with two slits, but also configurations with three and more slits—Sorkin detected that third-order (and higher-order) interference is not possible in quantum mechanics. The EPR experiments show that quantum mechanics involves nonlocal correlations which are demonstrated in a violation of the Bell or CHSH inequality, (...) but are still limited by a bound discovered by Tsirelson. It now turns out that Tsirelson’s bound holds in a broad class of probabilistic theories provided that they rule out third-order interference. A major characteristic of this class is the existence of a reasonable calculus of conditional probability or, phrased more physically, of a reasonable model for the quantum measurement process. (shrink)

This paper starts from a nonlinear fermion field equation of motion with a strongly coupled self-interaction. Nonperturbative quark solutions of the equation of motion are constructed in terms of a Reggeized infinite component free spinor field. Such a field carries a family of strongly interacting unstable compounds lying on a Regge locus in the analytically continued quark spin. Such a quark field is naturally confined and also possesses the property of asymptotic freedom. Furthermore, the particular field self-regularizes the interactions and (...) naturally breaks the chiral invariance of the equation of motion. We show why and how the existence of such a strongly coupled solution and its particle-family, wave duality forces a change in the field equation of motion such that it conserves C, P, T, although its individual interaction terms are of V-A and thus C, P nonconserving type. (shrink)

The question of some of the friends is: -/- How is it possible to explain “Double slit experiment” by “Fuzzy time-Particle Interpretation”?

In 1909, Einstein derived a formula for the mean square energy fluctuation in blackbody radiation. This formula is the sum of a wave term and a particle term. In a key contribution to the 1926 Dreim¨.

The idea of obtaining a pilot-wave quantum theory on a lattice with discrete time is presented. The motion of quantum particles is described by a \-distributed Markov chain. Stochastic matrices of the process are found by the discrete version of the least-action principle. Probability currents are the consequence of Hamilton’s principle and the stochasticity of the Markov process is minimized. As an example, stochastic motion of single particles in a double-slit experiment is examined.

If one starts from de Broglie's basic relativistic assumptions, i.e., that all particles have an intrinsic real internal vibration in their rest frame, i.e., hv 0 =m 0 c 2 ; that when they are at any one point in space-time the phase of this vibration cannot depend on the choice of the reference frame, then, one can show (following Mackinnon (1) ) that there exists a nondispersive wave packet of de Broglie's waves which can be assimilated to the (...) nonlinear soliton wave U 0 introduced by him in his double solution model of wave mechanics. (2) Since de Broglie's linear pilot waves can be considered to be real waves propagating as collective motions on a covariant subquantum chaotic “aether,” (3) these new solition waves can be considered as describing the particle's immediate neighborhood, i.e., the aether's reaction to the particle's motion in the stochastic interpretation of quantum mechanics. The existence of such a physical aether (which provides a perfectly causal interpretation of the action-a-distance implied by the Einstein-Podolsky-Rosen experiments) can now be proved by establishing the reality of de Broglie's waves in realizable experiments. (shrink)